html,
body,
#app {
    width: 100%;
    height: 100%;
}

#app {
    background-color: #eee;
}

* {
    padding: 0;
    margin: 0;
}

.flex {
    display: flex;
}

.flex-col {
    flex-direction: column;
}

.flex-1 {
    flex: 1;
}